A limitation in the current state of the art of solar panels is that they are often considered to stand out as unattractive and degrading to the architecture or landscaping that they are installed on or near. For example, an authentic Mexican tile roof on a hacienda in California or Arizona is distractingly marred by the presence of solar panels mounted there. Likewise, the look of a historical building, which would benefit from the green energy of solar panels, would be ruined by the presence of solar panels. In some cases, legal action has been taken to prevent the construction of arrays in certain areas, solely because of how they look. If solar panels could be made to have a more pleasing appearance, or to blend in better with their surroundings, their use would be greatly expanded. However, the panels rely on a broad spectrum of wavelengths for efficiency, necessitating that they be maximally exposed to sunlight, which limits any decorative methods to those that are able to minimize interference with the amount of convertible energy reaching the cells.
Advances in the field of optics motivated by a need to push beyond diffraction limits have led to experimental nano-based technologies pertaining to extraordinary optical transmission and reflection. The reflective properties of annular nanorod arrays have been demonstrated by Xie, Chen, Li and others. The targeted applications of this research have so far been in the areas of sub-diffraction limits in microscopy and imaging.
Applying these phenomena to solar panels, engineered reflective optical elements exhibiting extremely narrow wavelength bands of reflectivity would thus enable the generation of visible color images on the surfaces of solar panels while minimizing the loss of light converted by the panels. In this application, a single element reflects a single color, while groups of elements are combined to create a wide range of colors. Three elements with three corresponding center wavelengths, for example 660 nm (red), 565 nm (green) and 480 nm (blue), can be combined by controlling the percentage of reflectivity of each band to produce a gamut of colors. Unlike pigments, however, which reflect their ‘color’ while absorbing the other color wavelengths, the elements created by the method of the present invention reflect at the predetermined wavelength, while allowing wavelengths outside the reflective band to pass through the surface with little or no attenuation.
In the current art, the methods of creating nano-hole and nano-structure arrays is complex and time consuming, and the fabrication cost of such arrays is several orders of magnitude higher than would be commercially viable for a widely marketable product.
In view of this, it would be desirable to develop a method or methods of constructing or fabricating low cost nano-hole and nano-structure arrays.